10
4.5
Take Measurement
Pour your sample solution into the #1 or #2 sample vial (bottle). Rinse
electrode with distilled/deionized water and shake off excess water; insert
the probe into sample solution, stir gently and let it stand still; when
icon appears and stays, take the reading. Press to save the
measurement data. As shown in picture (4-5), calibrating method is B2 and
B3, temperature of solution is 25.0℃, water hardness measurement is 2.88×10-1, unit is mmol/L,
press to switch to other units.
4.6
Notes during Measurement Taking
4.6.1 Electrode must be rinsed thoroughly with distilled/deionized water before measuring. The
container for diluted and concentrated solutions should be separated. When testing, try to test
diluted solution first and then test concentrated solution.
4.6.2 Generally, calibration is necessary before every test, but if interval between tests is short, then
calibration isnot necessary; To test ifthe meter is due for calibration, simplyinsert the electrode
in one of the calibration solutions and wait for a stable reading. If the reading is within the
stated error range, then it is unnecessary to recalibrate.
4.6.3 When testing boiler water, users should choose B1/B2 calibration method, and add Ionic
Strength Buffer (TISAB) into B1, B2 calibration solution and soaking solution. Otherwise, it
will cause a significant measurement error; the proportion is add 50.4mg ACS grade Sodium
Bicarbonate (NaHCO3) per 100mL solution.
4.6.4 According to the isothermal measurement principle, the closer the test sample’s temperature is
to the calibration solution’s, the higher the accuracy of the measurement. So this principle is
recommended to follow when conducting tests. For general testing, the temperature discrepancy
between calibration solution and sample solution should be less than 15°C; for high accuracy
testing, the temperatures of calibration solution and sample solution should be consistent.
4.6.5 The sensor membrane of the electrode might become turbid after usage, which is a normal
phenomenon.
4.6.6 During usage, if you findthe PVC sensor membrane in the electrode measuring head is seriously
concave, please first screw it loose, then screw it tight, and then shake it forcefully for several
times to eliminate the air bubble, which should solve the problem.
4.6.7 When the concentration of sample solution is greater than 1.00×10mmol/L, icon will
display on the left-bottom corner, reminding users to dilute the sample solution 10 times before
testing; then multiple the readings by 10 to get the realreadings.
